1. Field of the Invention
The present invention relates to a key actuating system which controls or adjusts the reaction force of a key due to an applied force when a person plays a keyboard musical instrument or a clavier by hand.
Priority is claimed on Japanese Patent Application No. 2006-239500, filed Sep. 4, 2006, the content of which is incorporated herein by reference.
2. Description of Related Art
In the prior art, there are keyboard musical instruments such as electric keyboards and acoustic pianos which have actuators such as solenoids for operating or actuating keys independently (for example, see Japanese Unexamined Patent Application, First Publication NO. H02-254494, hereinafter a patent document 1, and Japanese Unexamined Patent Application, First Publication NO. H04-204697, hereinafter a patent document 2). Such keyboard musical instruments can operate or actuate each of the keys by using the actuators in accordance with music information corresponding to a sequence of sounds which constitute music, and can automatically play the music.
Various conventional keyboard musical instruments have been proposed and one of such the keyboard musical instruments, as described in the patent document 1, has a position sensor which detects operations or movements of the keys. Therefore, the keyboard musical instrument disclosed in the patent document 1 is constituted so as to be able to appropriately operate the keys upon automatically playing the instrument by using the actuators based on detection results of a position sensor.
Moreover, by using an electric keyboard musical instrument disclosed in the patent document 2 which generates electric sounds, it is possible to switch between an automatic playing mode and a manual playing mode. Furthermore, in this manual playing mode, the reaction force (braking force of the key) is affected by a pushing force on the key when a player pushes the key by his/her finger. Therefore, the patent document 2 discloses a constitution with an object of having the reaction force of the key feel like that of a natural or non-electric keyboard musical instrument. The patent document 2 applies the reaction force because, with respect to the electric keyboard musical instruments, the reaction force of the key is much lighter than that of natural or non-electric keyboard musical instruments.
On the other hand, with respect to natural or non-electric keyboard musical instruments, natural sounds are generated in a manner such as by hitting strings, and portions of the instrument which are moved or operated are heavy if they correspond to lower sounds. Therefore, there is a problem in which a larger force is necessary to push or operate the key for lower sounds than a portion for higher sounds, and it is difficult to quickly push the keys. Moreover, for a beginner, a child and a middle-age or old person, it is difficult to play the above-described natural or non-electric keyboard musical instruments.
It should be noted that the patent document 1 and 2 cannot solve the above-described problems. That is, the patent document 1 discloses a constitution in which the keys are merely actuated or operated by using the actuators in the case of automatic operation, and moreover, in the patent document 2, the reaction force is applied in order to obtain a feeling of pushing the key of a natural or non-electric keyboard musical instrument. Therefore, in both cases, it is not possible to reduce power or force which is necessary for pushing the keys when a keyboard musical instrument is manually played.